The one big thing Google Voice doesn't offer, besides automated telemarketer taunting, is free voice-over-internet phone calling through your cellphone. On an Android phone, however, you can use the Gizmo5 service, Google Voice, and a free application to call anyone for free.

A free, open-source, and unofficial Android app, Guava, gives any Android phone the ability to make and take calls over Gizmo5's VoIP service, connected through a Google Voice phone number. It works over Wi-Fi, 3G, or, for the daring, EDGE. You probably won't want to use Guava as your primary phone call manager, as the call quality varies with your connection and really works best over Wi-Fi. That said, if you're running up against your minute allotment, or find yourself in a basement-like spot with decent Wi-Fi but really bad cell coverage, Guava is a great little tool to have at your disposal.

It's also worth noting that, depending on who your carrier is, making a VoIP call over an EDGE or 3G network may violate your contract's terms of service. A little "hard" data use now and then likely won't be noticed, but if you plan on using Guava heavily with your cellular data plan, you should check and read into what's tolerated and what's not before embarking on your bold data-only adventure.

What you'll need:

Android-powered phone: Pretty much any model and nationality of the HTC Dream (T-Mobile G1), Magic (T-Mobile myTouch 3G), or Hero should work.

The Guava app: Head to your phone's Settings, then Applications menu, and ensure the "Unknown sources" option is checked. Then simply point your browser to that link and click the stand-alone Guava link to download the .apk installer.

Decent Wi-Fi or 3G service: At least to test out Guava and make your first test call. You can set Guava to call over EDGE connections, and even specify how many reception bars are required to try a call, but it's likely not worth the hassle.

Setting up Guava

If you've already set up Gizmo as a Google Voice phone, most of the grunt work is out of the way. Guava needs only your account names and passwords for both services to get working. That said, you'll probably want to poke around in the options (click the Menu button with the app open to get to them) to control when and how Guava makes calls over data connections. We've captured and explained Guava's options panels in a little gallery below. Click on the thumbnails for a larger view and description of the options there:

Making calls with Guava

When you first launch Guava—or head back to the main screen after all that setup tweaking—you'll see a pretty simple screen divided into making calls and sending SMS messages. The SMS portions are a little redundant, and not half as powerful as the Google Voice Android app. The calling function, on the other hand, is where the VoIP magic happens. If you just want to make a straight-up phone call, type in the number like you would in Google Voice and hit the Call button. Click on the bar above the number entry, though, and you can re-route your call to a username at Google Talk or Gizmo, or, if you've bought some OpenSky credits, to Skype users.

When Guava's loaded and can connect to Gizmo through the data services you selected in the options, it puts a little green pulse in your notifications tray. That serves as both a handy shortcut to the Guava app for making calls, and a reminder when you have it turned on, as it will try and accept your calls over a data connection if you leave it running. That shortcut comes in handy when you want to turn Guava off, because you have to (unfortunately) head to the app's settings and flip off the "Enabled" switch. I had success in three out of four phone calls making and receiving phone calls over Guava, with two outgoing calls coming through okay and one incoming call picking up just fine. Another call left me unable to hear the other party, but I can't exactly eliminate all the vagaries of modern telecommunications from the test.

When you place a call through Guava, it doesn't route through the main call screen, but replicates its look and feel with a pretty serious facsimile. The main niggling point to note is that hitting the red power/hangup button on your phone won't actually hang up a call—that's what the on-screen hangup and physical back button do in a Guava call. You can put a call on hold or speakerphone from the options menu, and hang up from there as well. I haven't seen what happens when another caller hits your Google Voice number during a Guava call, so if you can verify whether Guava supports call waiting or conferencing, be sure to tell us in the comments.

As far as Guava goes, that's about all there is to say at this point. Your mileage will certainly vary based on your Wi-Fi or 3G connection, phone stability, and other factors, but when Guava works, it's a reassuring bit of forward-looking, data-centric phone life.

Advertisement

Tell us how you're liking Guava and free VoIP calling, or any other features or issues you find with it not covered here, in the comments.